Ok,i looked and looked but really can't seem to find any pics of refugiums that are not in a sump...atleast in detail. I have a 20L that i need to build and was wondering if i should use any dividers or anything. I plan on drilling it for the return,but did'nt know if an overflow was needed.It is going to be inline w a stock and frag tank,being fed by the return of the sump. Here is a pic of my mocked up system. The pipe going into the fuge continues into the frag tank via spray bars..it comes from the stock tant return(kinda hard to see/follow.